What Are Some Of Your Favourite B-Sides and Rarities Albums?

I almost forgot about Thomas Dolby and his debut The Golden Age of Wirless (1982). A superb synth-pop record which was finally handed a great upgrade back in 2009 along with several unreleased demos and bonus tracks, some that where just as good or even better than what made it onto the final material:

Airwaves (1981)

This one have been posted as an "alternative" version, however I do think it is the real original demo version from either 1979 or 1981, as Dolby wrote in the liner notes of the 2009 re-release that it was written back in 80 or 81 and would later on be part of a compilation called From Brussell with Love.
This is a far more "downbeat" or fragile version than the album version later on, but I think it is just as good or maybe more atmospheric is the right word.

Incredible that I almost forgot one of my earliest and yet most important music discoveries as a 12 year old, then through the german dance/techno act Scooter and the double album release of Rough and Tough and Dangerous – The Singles 94/98.
I can look back a "laugh" about it, but really they where the ones who made me interested in music, not just listening to a single or a song on the radio every now and then, but hearing an entire album through, several times over and then trying to find similar sounding artists and their albums and so on.
Anyway, I got this in early winter of 1998 as a late Christmas gift from a cousin of mine, and I had heard several of their singles before, (in norway they always seemed to be huge during the mid 90s and early 00s) so I was not exactly new to their sound, but it was really on disc 2 where the real deal lied, as it collected more or less remixes, unreleased material and B-Sides which to my surprise was not just better but really outshined the big hit singles on disc 1 almost every time.
It is a real shame they never went on to make a full record only with the B-Sides and instrumental that was done during their earlier days of 1993-1996, as there really where some real gems on this 1998 release. No german screaming or shouting, no smurf high-pitched bullshit or samples of big and overplayed hits of the 70s or 80s, just dreamy and relaxing dance/trance that just keep on building upwards:

Rhapsody in E (1994)

Back in Time (1995)

Across the Sky (1995)

I'm Raving - Taucher remix (1996) 

Not a b-side but a stunning remix of their 1996 hit I'm Raving by DJ Taucher.
Surely one of the most beautiful trance tunes of the mid 90s, or so I think. Pisses all over the original single and they should have released this one instead, at least onto the album Wicked (1996).